What is the Principal field?

It is who the policy grants access to. Enter a 12-digit AWS account id (expanded to its root ARN), an asterisk for everyone, or any IAM ARN.

What does the key prefix do?

It scopes the permission to objects under a path, for example `logs/` produces the resource `arn:aws:s3:::bucket/logs/*` so only that subtree is affected.

When should I include the bucket ARN?

Tick that option for ListBucket-style permissions, which apply to the bucket itself rather than its objects. It adds `arn:aws:s3:::bucket` alongside the object ARN.

S3 Bucket Policy Generator

Generate an AWS S3 bucket policy JSON for a principal, actions, and prefix.

Policy inputs

Bucket name

Effect

Principal (account id / * / ARN)

Actions (one per line)

Key prefix (optional)

Also include the bucket ARN (ListBucket-style)

Generated policy

{
  "Version": "2012-10-17",
  "Statement": [
    {
      "Effect": "Allow",
      "Principal": {
        "AWS": "*"
      },
      "Action": "s3:GetObject",
      "Resource": "arn:aws:s3:::my-bucket/*"
    }
  ]
}

client-side

JSON

About this tool

Build an AWS S3 bucket policy for a principal, a set of actions, and an optional key prefix. Copy valid JSON. Free and client-side. S3 Bucket Policy Generator runs in the browser on DevTools. There is no signup, and your input stays on this device unless the tool explicitly performs a live network lookup.

What this tool does not do

S3 Bucket Policy Generator is a free in-browser utility, not a hosted API. It does not keep server-side history and is not a substitute for production verification in your own stack.

How do I use this tool?

How do I use S3 Bucket Policy Generator?
Open S3 Bucket Policy Generator, enter or paste your input, and copy the result. The page works without an account.

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